1. Field of the Invention
The present invention relates to a cathode ray tube device, and more particularly to a projection type cathode ray tube device which is applicable to a projection type image display device such as a projection type TV receiver, a video projector or the like.
2. Description of the Related Art
In general, three projection type cathode ray tube devices which emit respective colors of red, green and blue are mounted on a projection type image display device, wherein images of respective projection type cathode ray tubes are magnified by respective projection lenses arranged at frontal sides of respective panel portions and are projected onto a screen and synthesized. In each projection type cathode ray tube device, from a phosphor screen toward an electron gun, a deflection yoke, a convergence yoke, an alignment magnet and the like are sequentially mounted and arranged, wherein electron beams irradiated from the electron guns receive a deflection action due to a deflection magnetic field which is generated by a deflection yoke and reach the phosphor screen.
In the projection type image display device, the distortion of luster or the misalignment of three-color luster (also referred to as “color slurring” or “misconvergence”) due to the magnetic field generated in a convergence yoke served for aligning the images projected from the above-mentioned three projection type cathode ray tubes on a screen is corrected so as to obtain image with no color slurring. Here, as this type of projection type cathode ray tube device, a cathode ray tube device disclosed in Japanese Unexamined Patent Publication 287845/1996 or the like can be named.